Corrective voice prompts for caregiving device

ABSTRACT

A medical device such as a defibrillator that incorporates corrective voice prompts that navigate users around operator errors. The voice prompts may, for example, address errors of readiness (e.g., failing to connect the defibrillator to an AC power source, failing to pre-connect electrodes, etc.), errors of omission (i.e., forgetting to do something, such as attempting to deliver a shock before the defibrillator is charged), and errors of commission (i.e., doing the wrong thing, such as attempting to shock VF when in the synchronization mode). The voice prompts may address errors in the delivery of therapy (e.g., attempting to shock VF when in the synchronization mode) or they may address errors other than in the delivery of therapy (e.g., failing to connect to an AC power source).

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.10/952,451, filed on Sep. 28, 2004 now U.S. Pat. No. 7,729,757, whichapplication is a continuation in part of U.S. application Ser. No.10/841,367, filed on May 7, 2004 now U.S. Pat. No. 7,706,878, andentitled, “Automated Caregiving Device with Prompting Based on CaregiverProgress” (both incorporated herein by reference).

BACKGROUND

Defibrillators and defibrillator-external pacemakers are employed torestore and maintain a heart's normal rhythm in either an emergencysituation such as cardiac arrest, or voluntarily to normalize a person'srhythm in non-life threatening situations (e.g., atrial fibrillation).

Use of a defibrillator requires specific certification resulting fromsuch programs as the American Heart Association's Advanced Life or BaseLife Support courses. Further institutional or organizational trainingor competency evaluation may also be required. These requirementsgenerally remain true for both manual and semi-automatic (AED)defibrillators. In order to maximize familiarity with this lifesavingequipment, institutions and organizations generally require periodicrecertification and or demonstration of competency. In part, thesetraining requirements are an attempt to maximize an operator's chance ofsuccessfully using a defibrillator.

Use of a defibrillator, particularly in emergency situations, places agreat deal of stress on its operator. As such, even trained users stillmake mistakes when trying to operate a defibrillator. At least one studyhas demonstrated that upwards of 50 percent of defibrillator failurescan be attributed to operator errors. Failure to use the defibrillatorcorrectly can cause delays and compromise therapy. Bone, DefibrillatorFailures: Causes and Problems and Recommendations for Improvement, JAMA,Vol. 264, No. 8 (1990).

Another factor contributing to operator errors is that many institutionsand organizations possess different models of defibrillators that employdifferent operating interfaces, terminology, etc. The difference inoperating systems can cause delays and mistakes, both of which maycompromise therapy.

Operators are generally required to perform daily test and maintenanceon a defibrillator. Such activities may require operation from a DC(battery) source that leads one to disconnect the defibrillator from ACpower, source. It is not beyond reason that an operator, aftercompleting a daily test might leave the defibrillator in the powered oncondition, and not connect to the AC power source. Such conditions woulddrain the battery and render the defibrillator therapeutically useless.Another such example might be the disconnecting of therapeuticelectrodes for daily test purposes. If not reconnected, delays mightresult that compromise therapy.

The current state of the art employs visual prompts or nonspecific tonesto communicate user errors, and/or communicate corrective actions todefibrillator operators. FIG. 6 gives an example of a prior art visualprompt for communicating a user error. A recognized shortcoming ofvisual prompts is that they can be easily overlooked under the stress ofan emergency situation. They are passive as this approach relies on anoperator looking specifically at the display field at all times. NewerAED defibrillators have taken the step of incorporating graphic promptsor icons into the physical design and labeling of the product in orderto give them more permanency.

In an attempt to overcome these shortcomings, some defibrillators haveincorporated a variety of high and low pitched tones as alert alarms todraw attention to the device. Initially successful, their shortcominghas become a lack of specificity. Over the years there has beenproliferation of tonal alarms on a variety of medical equipment likelyto be present in an emergency resuscitation. Further, the growing trendtoward incorporating more vital sign parameters into pre-hospitaldefibrillators also raises the number of warning tones rescuers mustdecipher.

In recent years voice prompts have been employed to simplify thetherapeutic use of defibrillators. That is they guide users, someminimally trained, through the setup and use of a defibrillator fordelivery of a potentially lifesaving electrical shock (e.g., attachingelectrodes, prompting need for CPR, and shock delivery). Most recently,defibrillators have begun to expand the range of the voice prompting toinclude the ABCs (airway, breathing, chest compressions) ofresuscitation, and to provide feedback on the quality and rate of chestcompressions. Olson U.S. Pat. No. 5,792,190 and Edward U.S. ApplicationNo. 2003/0216785 describe the use of voice prompts as part of an AEDinterface; they generally describe the role of voice prompts asinstructions for a series of operations performed by the operator forthe treatment of a patient, including the deployment and use of an AED.Nova U.S. Pat. Nos. 6,334,070 and 6,697,671 and Snyder U.S. Pat. No.6,356,785 expand the use of therapeutic voice prompts to include BLS andALS treatment protocols; operational faults are communicated to theoperator by visual indicators (e.g., LED) or non-specific tonal sounds.Stendahl U.S. Pat. No. 5,955,956 describes the use of an audible alarmsystem in an AED in response to processor detected faults that are foundduring a periodic self-test. Borgenicht U.S. Pat. No. 6,405,082describes the use of tonal and verbal prompts to confirm the therapeuticmodes of a defibrillator, i.e., to alert the operator that thedefibrillation mode has been selected, or that one is charging forsynchronized cardioversion.

SUMMARY

In general, the invention features a medical caregiving device (e.g.; adefibrillator) that incorporates corrective voice prompts that navigateusers around operator errors. The voice prompts may, for example,address errors of readiness (e.g., failing to connect the defibrillatorto an AC power source, failing to pre-connect electrodes, etc.), errorsof omission (i.e., forgetting to do something, such as attempting todeliver a shock before the defibrillator is charged), and errors ofcommission (i.e., doing the wrong thing, such as attempting to shock VFwhen in the synchronization mode). The voice prompts may address errorsin the delivery of therapy (e.g., attempting to shock VF when in thesynchronization mode) or they may address errors other than in thedelivery of therapy (e.g., failing to connect to an AC power source).

In general the invention features a medical device of the type used forassisting a user in delivering therapy to a patient, the devicecomprising a user interface including a speaker configured to delivervoice prompts to a user to assist the user in operating the device; atleast one sensor or circuit element configured to detect an error madeby the user in operating the device; a memory in which a plurality ofdifferent voice prompts are stored; a processor configured to determinewhich of the different voice prompts should be selected for deliverybased on the detected error; and circuitry configured to work with thememory and the user interface and speaker to deliver the selected voiceprompt.

In preferred implementations, one or more of the following features maybe incorporated. The device may include a defibrillator. The selectedvoice prompts may address errors in the delivery of therapy, or they mayaddress errors other than errors in the delivery of therapy. The voiceprompts may include a prompt to correct the user's error in failing toselect the defibrillation mode. The voice prompts may include a promptto correct the user's error in selecting synchronized delivery ofelectrical stimulation during a cardiac arrest situation. The voiceprompts may include a prompt to correct the user's error in failing tocharge the defibrillator's battery. The voice prompts may include aprompt to correct the operator's failure to connect the device to ACpower. The voice prompts may include a prompt to correct operator errorsassociated with the storage, management, deletion, transmission, orcorrection of information. The voice prompts may include a prompt tocorrect operator errors associated with the use of removable forms ofmedia. The voice prompts may include a prompt to correct operator errorsassociated with the use of wired or wireless transmission of data. Thevoice prompts may include a prompt to correct operator errors associatedwith recording, displaying, storing, or printing of electrocardiographic(ECG) data. The voice prompts may include a prompt to correct operatorerrors related to analysis of electrocardiographic (ECG) data. The voiceprompts may include a prompt to correct operator errors associated withvital signs monitoring. The vital signs monitoring may comprise one ormore of the following: heart rate, temperature, blood pressure(non-invasive and invasive), pulse oximetry, end tidal CO2, respiration,blood gases, CO, or blood chemistries. The voice prompts may include aprompt relating to errors in calibration, sensor replacement,environmental issues (i.e. high ambient lighting), or cable placement.The voice prompts may include a prompt to correct operator errorsassociated with transcutaneous pacing. The voice prompts may include aprompt relating to increasing or decreasing pacing rate.

Providing voice prompts rather than audible tones or visual informationon a display provides a much more effective means of informing the userof an error, and of informing him of how to correct that error. Thevoice prompts get the attention of the user, and they are more effectiveat getting the user to take appropriate action.

Other features and advantages of the invention will be found in thedetailed description, drawings, and claims.

The details of one or more embodiments of the invention are set forth inthe accompanying drawings and the description below. Other features,objects, and advantages of the invention will be apparent from thedescription and drawings, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram illustrating one implementation of theinvention.

FIG. 2 is a block diagram illustrating a second implementation of theinvention.

FIG. 3 is a block diagram illustrating a third implementation of theinvention.

FIG. 4 is a perspective view of an automatic external defibrillator(AED) of a type that could incorporate one or more implementations ofthe invention.

FIG. 5 is a block diagram of at least a portion of an AEDimplementation.

FIG. 6 is a view of a prior art defibrillator display showing a visualprompt for communicating an error to a user.

FIG. 7 is a table listing examples of non-therapy-delivery errors forwhich voice prompts could be delivered

FIG. 8 is a table listing examples of therapy-delivery errors for whichvoice prompts could be delivered.

DETAILED DESCRIPTION

There are a great many possible implementations of the invention, toomany to describe herein. Some possible implementations that arepresently preferred are described below. It cannot be emphasized toostrongly, however, that these are descriptions of implementations of theinvention, and not descriptions of the invention, which is not limitedto the detailed implementations described in this section but isdescribed in broader terms in the claims.

FIG. 1 depicts one possible manner in which voice prompts may be used tocorrect operator errors of a type that could generally be called errorsof omission. In this implementation, the operator presses (12) thebutton designated for shock delivery. The microprocessor controlledlogic initially detects (14) whether the defibrillator is in thedefibrillator mode (e.g., it may be in the pacing mode). If it is not inthe defibrillator mode, a voice prompt is delivered (16) to the operatorto “Select the Defibrillator Mode.” Alternately, the defibrillator modemay have already been selected, but the operator may have failed tocharge the defibrillator. If this is detected (18), the defibrillatormay prompt (20) the operator to “Press the Charge Button.” The sameapproach may be applied to the pacing mode, to cardioversion, and toother applications.

FIG. 2 depicts another implementation, in which voice prompts are usedto correct operator errors of a type that could generally be callederrors of commission. In this implementation, the defibrillator promptsthe operator (22) regarding a user-created problem that blocks thedelivery of therapy. For example, if the synchronization mode iserroneously activated during the treatment of a cardiac arrestcondition, the depicted logic and resulting voice prompt will guide theoperator around the self-generated problem. If the logic has determinedthat the synchronization mode has been selected, it then determines (24)whether there are R waves present. If so, then it may prompt (26) theoperator to remove the synchronization selection.

FIG. 3 depicts the concept of a “sentinel” that continuously monitorscritical defibrillator functions and operations; this implementationcould be regarded as assisting in correction of readiness errors. Inthis implementation, the logic monitors (28) the connection to an ACpower source. If the defibrillator were to be left unplugged, thedefibrillator could prompt (30) “Plug Defibrillator In.” Further, as thecriticality of a situation increased, it could change the content of thevoice prompt and/or the frequency of the prompt.

Other examples of errors that could be corrected by voice promptsinclude: (1) the operator's failure to insert a memory card into thedevice; (2) the operator's failure to make an online connection prior toattempting to send data; (3)

Preferably, a voice prompt does more than alert the user of an error; itgoes on to instruct the user as to the corrective action that needs tobe taken.

FIG. 4 shows the exterior of an automatic external defibrillator 10 of atype that might incorporate the voice prompts disclosed herein.

FIG. 5 shows some of the basic functional blocks that would beimplemented in an external defibrillator (e.g., an AED) thatincorporated the implementations disclosed herein. Sensors 20 withassociated signal conditioning 122 and detection circuitry 124 provideinformation to a processing unit 126 as to errors that have occurred.The processor uses the information to direct an audio system 128 todeliver voice prompts (which are stored in memory 138) from a speaker130. The processor may also cause information to be presented on adisplay 132 or draw the user's attention to graphical images 134 (e.g.,by lighting up the images or activating lights adjacent to the images).A microphone 136 may be used to record information during an event.

FIGS. 7-8 are tables listing examples of non-therapy-delivery errors forwhich voice prompts could be delivered (FIG. 7) and therapy-deliveryerrors for which voice prompts could be delivered (FIG. 8) As the tableindicates, the voice prompts may include prompts for correcting a widevariety of errors. The voice prompts may include a prompt to correct theuser's error in failing to select the defibrillation mode. The voiceprompts may include a prompt to correct the user's error in selectingsynchronized delivery of electrical stimulation during a cardiac arrestsituation. The voice prompts may include a prompt to correct the user'serror in failing to charge the defibrillator's battery. The voiceprompts may include a prompt to correct the operator's failure toconnect the device to AC power. The voice prompts may include a promptto correct operator errors associated with the storage, management,deletion, transmission, or correction of information. The voice promptsmay include a prompt to correct operator errors associated with the useof removable forms of media. The voice prompts may include a prompt tocorrect operator errors associated with the use of wired or wirelesstransmission of data. The voice prompts may include a prompt to correctoperator errors associated with recording, displaying, storing, orprinting of electrocardiographic (ECG) data. The voice prompts mayinclude a prompt to correct operator errors related to analysis ofelectrocardiographic (ECG) data. The voice prompts may include a promptto correct operator errors associated with vital signs monitoring. Thevital signs monitoring may comprise one or more of the following: heartrate, temperature, blood pressure (non-invasive and invasive), pulseoximetry, end tidal CO2, respiration, blood gases, CO, or bloodchemistries. The voice prompts may include a prompt relating to errorsin calibration, sensor replacement, environmental issues (i.e. highambient lighting), or cable placement. The voice prompts may include aprompt to correct operator errors associated with transcutaneous pacing.The voice prompts may include a prompt relating to increasing ordecreasing pacing rate.

Many other implementations of the invention other than those describedabove are within the invention, which is defined by the followingclaims. For example, the invention can be applied to externaldefibrillators of the type used within the hospital as well as outsidethe hospital.

1. A medical device of the type used for assisting a user in deliveringtherapy to a patient, the device comprising a user interface configuredto deliver prompts to a user to assist the user in operating the device;at least one sensor or circuit element configured to detect an errormade by the user in the manner in which the user operates the device,the error comprising the operator's failure to connect the device to ACpower a memory in which a plurality of different prompts are stored; aprocessor configured to determine which of the different prompts shouldbe selected for delivery based on the detected error; and circuitryconfigured to work with the memory and the user interface to deliver theselected prompt to assist the user in correcting the error.
 2. A medicaldevice of the type used for assisting a user in delivering therapy to apatient, the device comprising a user interface configured to deliverprompts to a user to assist the user in operating the device; at leastone sensor or circuit element configured to detect an error made by theuser in the manner in which the user operates the device, the errorcomprising operator errors associated with the storage, management,deletion, transmission, or correction of information a memory in which aplurality of different prompts are stored; a processor configured todetermine which of the different prompts should be selected for deliverybased on the detected error; and circuitry configured to work with thememory and the user interface to deliver the selected prompt to assistthe user in correcting the error.
 3. A medical device of the type usedfor assisting a user in delivering therapy to a patient, the devicecomprising a user interface configured to deliver prompts to a user toassist the user in operating the device; at least one sensor or circuitelement configured to detect an error made by the user in the manner inwhich the user operates the device, the error comprising operator errorsassociated with the use of removable forms of media, a memory in which aplurality of different prompts are stored; a processor configured todetermine which of the different prompts should be to selected fordelivery based on the detected error; and circuitry configured to workwith the memory and the user interface to deliver the selected prompt toassist the user in correcting the error.
 4. A medical device of the typeused for assisting a user in delivering therapy to a patient, the devicecomprising a user interface configured to deliver prompts to a user toassist the user in operating the device; at least one sensor or circuitelement configured to detect an error made by the user in the manner inwhich the user operates the device, the error comprising operator errorsassociated with the use of wired or wireless transmission of data, amemory in which a plurality of different prompts are stored; a processorconfigured to determine which of the different prompts should beselected for delivery based on the detected error; and circuitryconfigured to work with the memory and the user interface to deliver theselected prompt to assist the user in correcting the error.
 5. A medicaldevice of the type used for assisting a user in delivering therapy to apatient, the device comprising a user interface configured to deliverprompts to a user to assist the user in operating the device; at leastone sensor or circuit element configured to detect an error made by theuser in the manner in which the user operates the device, the errorcomprising operator errors associated with recording, displaying,storing, or printing of data, a memory in which a plurality of differentprompts are stored; a processor configured to determine which of thedifferent prompts should be selected for delivery based on the detectederror; and circuitry configured to work with the memory and the userinterface to deliver the selected prompt to assist the user incorrecting the error.
 6. The medical device of claim 5 wherein the dataare electrocardiographic (ECG) data.
 7. A medical device of the typeused for assisting a user in delivering therapy to a patient, the devicecomprising a user interface configured to deliver prompts to a user toassist the user in operating the device; at least one sensor or circuitelement configured to detect an error made by the user in the manner inwhich the user operates the device, the error comprising operator errorsrelated to analysis of data, a memory in which a plurality of differentprompts are stored; a processor configured to determine which of thedifferent prompts should be selected for delivery based on the detectederror; and circuitry configured to work with the memory and the userinterface to deliver the selected prompt to assist the user incorrecting the error.
 8. The medical device of claim 7 wherein the dataare electrocardiographic (ECG) data.
 9. A medical device of the typeused for assisting a user in delivering therapy to a patient, the devicecomprising a user interface configured to deliver prompts to a user toassist the user in operating the device; at least one sensor or circuitelement configured to detect an error made by the user in the manner inwhich the user operates the device, the error comprising one or moreerrors in calibration, sensor replacement, environmental issues, ambientlighting, or cable placement, a memory in which a plurality of differentprompts are stored; a processor configured to determine which of thedifferent prompts should be selected for delivery based on the detectederror; and circuitry configured to work with the memory and the userinterface to deliver the selected prompt to assist the user incorrecting the error.